A chemical genetic strategy identify the PHOSTIN, a synthetic molecule that triggers phosphate starvation responses in Arabidopsis thaliana

Abstract

Summary Plants display numerous strategies to cope with phosphate (Pi)‐deficiency. Despite multiple genetic studies, the molecular mechanisms of low‐Pi‐signalling remain unknown. To validate the interest of chemical genetics to investigate this pathway we discovered and analysed the effects of PHOSTIN (PSN), a drug mimicking Pi‐starvation in Arabidopsis.We assessed the effects of PSN and structural analogues on the induction of Pi‐deficiency responses in mutants and wild‐type and followed their accumulation in plants organs by high pressure liquid chromotography (HPLC) or mass‐spectrophotometry.We show that PSN is cleaved in the growth medium, releasing its active motif (PSN11), which accumulates in plants roots. Despite the overaccumulation of Pi in the roots of treated plants, PSN11 elicits both local and systemic Pi‐starvation effects. Nevertheless, albeit that the transcriptional activation of low‐Pi genes by PSN11 is lost in the phr1;phl1 double mutant, neither PHO1 nor PHO2 are required for PSN11 effects.The range of local and systemic responses to Pi‐starvation elicited, and their dependence on the PHR1/PHL1 function suggests that PSN11 affects an important and early step of Pi‐starvation signalling. Its independence from PHO1 and PHO2 suggest the existence of unknown pathway(s), showing the usefulness of PSN and chemical genetics to bring new elements to this field.

Variation in ‘Bayou Belle’ and ‘Beauregard’ Sweetpotato Root Length in Response to Experimental Phosphorus Deficiency and Compacted Layer Treatments

“…Scant information is available about the temporal effects of -P root length in other plant species. However, Bonnot et al, (2016) have hypothesized that temporal P deficiency triggers local and long-distance (systemic) molecular, biochemical, and morphological responses in plants to adapt root systems to the heterogeneous distribution and availability of P in the soil. The current findings have implications in production environments, especially in relation to cultivar-specific responses to supplemental P fertilizer rates and spatial variation of soil P availability.…”

S‐Nitrosoglutathione works downstream of nitric oxide to mediate iron‐deficiency signaling in Arabidopsis

“…Chemical biology allows the use of small molecules to dose-dependently activate the function of a specific protein or disrupt the function of redundant proteins, thus eliminating plant lethality (Hicks and Raikhel, 2012;Serrano et al, 2015). Small-molecule-based chemical screening has been successfully used in many fields such as hormone signaling to identify receptors and phosphate homeostasis to dissect the molecular response (De Rybel et al, 2009;Park et al, 2009;Arnaud et al, 2014;Bonnot et al, 2016). Functional redundancy due to the overlapping roles of members within gene families, bHLH subgroups Ib and IVc, and lethality like FIT knockout appear to be limiting factors specifically altering the Fe-signaling network Wang et al, 2013;Zhang et al, 2015;Li et al, 2016;Liang et al, 2017).…”

Small-Molecules Selectively Modulate Iron-Deficiency Signaling Networks in Arabidopsis

“…Small-molecule-based chemical biology is an effective approach to dissect the nutrient-starvation response, especially signaling (Bonnot et al, 2016; Kailasam et al, 2018). In the current study, we investigated the role of two small-molecules, R3 and R6 in Fe deficiency response (Table 1).…”